(1) Field of the Invention
The present invention relates to a weight-lifting apparatus of the type including a plurality of weights mounted on a frame for generally vertical reciprocal movement by a force imparted by a person using the apparatus.
(2) Description of the Prior Art
Many conventional weight-lifting devices include a frame which supports the user and a plurality of weights mounted on the frame. The weights are mounted on guide rods for generally vertical reciprocal movement from a rest position upwardly against gravity force to an upper position. Lifting of the weights is accomplished by the user who actuates a bar or other device operably connected to the weights. For any exercise, the number of weights lifted can be selected by the user. In the case where the user is doing arm curls, for example, during the lifting stroke of the weight-lifting apparatus, the user grasps a bar with his hands and pulls upwardly to lift the weights operably connected to the bar. When the person has completed the lifting stroke of the bar, the bar is allowed to return to its rest position. During return of the bar to its rest position, the user restrains the bar so it moves slowly back to its rest position. In a conventional weight-lifting apparatus, the weight to be lifted by the user during the lifting stroke is the same as the weight that is restrained by the user during the return stroke.
It is known that a person lifting weights may be able to lift only a predetermined amount of weight but can restrain the movement of a larger amount of weight. Thus, for many exercises, a conventional weight-lifting apparatus under-utilizes a person's capability during the return stroke of the device. It would be desirable to provide a weight-lifting apparatus wherein the force required to restrain the weights during the return stroke is substantially greater than the force necessary to lift the weights.
In a weight-lifting apparatus designed for arm curls, the user places his arms on a table and grasps with his hands the bar that is operably connected to the weights. The portion of the arms that rest on the table are those located immediately above the elbow. The table is generally planar and positions the upper arms of the user at a given angle with respect to the bar being curled against the force of the weights. In a conventional apparatus for arm curls, the table is either fixed in position with respect to the bar being curled, or is pivotal with respect to the bar as is shown in U.S. Pat. No. 4,239,210 to Lambert. It is believed to be undesirable to allow the table to pivot as the bar is curled because pivoting of the table increases the leverage available to the user and thereby decreases the amount of force necessary to lift the weights. It would be desirable to provide a table which can be fixed during exercise, but which can be adjusted to vary its angle with respect to the bar. Thus, the user and his exerciser team could perform a series of curls with the table at one angle, thus exercising a portion of the muscles, and then change the angular orientation of the table and exercise another portion of the muscles.